同性恋是一个机制未明的生物学行为，研究显示遗传因素在同性恋的形成中起重要作用。我们前期的男性同性恋全基因组关联分析显示：位于Xq27.3的FMR1NB基因的SNP rs17320865与男性同性恋性取向显著相关，分析显示该基因主要在杏仁核高水平表达。本研究将采用原位杂交技术分析FMR1NB基因在男性同性恋与男性异性恋死亡后人脑杏仁核的mRNA表达差异性；运用影像遗传学技术，对4组携带风险型或保护型的男性同性恋和男性异性恋者，通过结构态和功能态磁共振成像技术，获取3D结构、静息态、弥散张量成像的多模态数据，分析组别之间杏仁核的灰质密度、平均弥散率、各向异性、局部一致性、低频振幅比例，以及杏仁核相关神经网络的结构和功能的差异性，评估遗传主效应、性取向主效应以及遗传-性取向交互作用。旨在初步阐明FMR1NB基因对男性同性恋杏仁核结构和功能的影响，这对揭示男性同性恋的生物学机制具有重要的科学意义。

Homosexuality is biological behavior, however, the mechanism is still unknown. Much studies showed that the genetic factor plays an important role in it. Our GWAS suggested that the SNP rs17320865 in FMR1NB gene was significantly associated with male homosexual preference in Chinese population. And we also found the gene was expressed highly in amygdala. This project will explore to compare the mRNA expression of FMR1NB gene in the amgydala of brain slices between homosexual and heterosexual men by in-situ hybridization techonology. And we also compare the difference in the measures of amygdala using muti-mode MRI data which include gray matter denstiy, mean diffusivity, fractional anisotropy, regional homogeneity, fractional amplitude of low-frequency fluctuation and connectome in four groups, i.e. homosexual men with or without risk genetype, heterosexual men with or without risk genetype. We will assess the major effect of gentic factor, sexual preference and interaction of them. And we want to interpret the effects of the FMR1NR gene on the structure and function of the amygdala. This project will extend our understanding of the biological mechanism of male homosexuality.